One day Malik Bhago, a high government official of the city, gave a general feast. He invited Guru Nanak too. Guru ji declined the invitation saying, 'We are fakirs, what have we to do with your feast?' On being asked a second time, Guru Nanak took Bhai Lalo with him and went to Malik Bhago's house.
With great anger Malik Bhago said to Guru ji, 'You are dishonoring Kshatriyas by eating dry chapaties in the house of a low caste carpenter. My feast will offer you delicious food. Why do you refuse to eat it?'
Guru Nanak said, 'Mr Malik! Your food is not pure. I cannot eat an impure food. Your blood soaked food does not agree with me so I do not like to take it.' The Malik said, 'it means the delicious dishes prepared by me are impure and are polluted with blood instead the crumbs of the Laalo's house are pure. How dare you say so, you should explain me how you made this bold statement?'
On hearing this Guru Nanak became serious. He said boldly that he would prove what he had said. He asked the Malik to bring the so called very delicious food from his kitchen. At the same time he asked for food to be brought from the house of Laalo. Then Guru Nanak took the Laalo's course bread in his right hand and Malik Bhago's delicious sweet breads in his left hand. Then he said to the Malik, 'Now I shall show you that your sweet and costly bread is impure and not fit for consumption.'
As the Guru pressed his both hands milk dropped from course bread of Bhai Laalo's and blood oozed from Malik Bhaago's delicacies.
Malik Bhaago was wonder struck and the entire assembly was lost in amazement. Then the Guru said to him, 'O Malik! You can see with your own eyes, there is blood of poor people in your delicacies. You have amassed the wealth at the cost of others. As your earnings are impure so your food is polluted. Bhai Laalo has earned his bread by honest labour. He also shares his earning with others. So his food is pure and sweet.
Malik Bhago became dumb. He considered himself to be a great sinner. He fell at the feet of Guru Nanak and asked him to pardon him.
Then Guru Nanak asked him to make an honest living. Malik Bhago became a changed man. He happily accepted Guru Nanak as his true Guru.